rev 55557 : 8217676: Upgrade libpng to 1.6.37
Reviewed-by: prr, jdv

   1 /*
   2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   3  *
   4  * This code is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 only, as
   6  * published by the Free Software Foundation.  Oracle designates this
   7  * particular file as subject to the "Classpath" exception as provided
   8  * by Oracle in the LICENSE file that accompanied this code.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  */
  24 
  25 /* pngmem.c - stub functions for memory allocation
  26  *
  27  * This file is available under and governed by the GNU General Public
  28  * License version 2 only, as published by the Free Software Foundation.
  29  * However, the following notice accompanied the original version of this
  30  * file and, per its terms, should not be removed:
  31  *
  32  * Last changed in libpng 1.6.26 [October 20, 2016]
  33  * Copyright (c) 1998-2002,2004,2006-2014,2016 Glenn Randers-Pehrson
  34  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  35  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  36  *
  37  * This code is released under the libpng license.
  38  * For conditions of distribution and use, see the disclaimer
  39  * and license in png.h
  40  *
  41  * This file provides a location for all memory allocation.  Users who
  42  * need special memory handling are expected to supply replacement
  43  * functions for png_malloc() and png_free(), and to use
  44  * png_create_read_struct_2() and png_create_write_struct_2() to
  45  * identify the replacement functions.
  46  */
  47 
  48 #include "pngpriv.h"
  49 
  50 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
  51 /* Free a png_struct */
  52 void /* PRIVATE */
  53 png_destroy_png_struct(png_structrp png_ptr)
  54 {
  55    if (png_ptr != NULL)
  56    {
  57       /* png_free might call png_error and may certainly call
  58        * png_get_mem_ptr, so fake a temporary png_struct to support this.
  59        */
  60       png_struct dummy_struct = *png_ptr;
  61       memset(png_ptr, 0, (sizeof *png_ptr));
  62       png_free(&dummy_struct, png_ptr);
  63 
  64 #     ifdef PNG_SETJMP_SUPPORTED
  65          /* We may have a jmp_buf left to deallocate. */
  66          png_free_jmpbuf(&dummy_struct);
  67 #     endif
  68    }
  69 }
  70 
  71 /* Allocate memory.  For reasonable files, size should never exceed
  72  * 64K.  However, zlib may allocate more than 64K if you don't tell
  73  * it not to.  See zconf.h and png.h for more information.  zlib does
  74  * need to allocate exactly 64K, so whatever you call here must
  75  * have the ability to do that.
  76  */
  77 PNG_FUNCTION(png_voidp,PNGAPI
  78 png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
  79 {
  80    png_voidp ret;
  81 
  82    ret = png_malloc(png_ptr, size);
  83 
  84    if (ret != NULL)
  85       memset(ret, 0, size);
  86 
  87    return ret;
  88 }
  89 
  90 /* png_malloc_base, an internal function added at libpng 1.6.0, does the work of
  91  * allocating memory, taking into account limits and PNG_USER_MEM_SUPPORTED.
  92  * Checking and error handling must happen outside this routine; it returns NULL
  93  * if the allocation cannot be done (for any reason.)
  94  */
  95 PNG_FUNCTION(png_voidp /* PRIVATE */,
  96 png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
  97     PNG_ALLOCATED)
  98 {
  99    /* Moved to png_malloc_base from png_malloc_default in 1.6.0; the DOS
 100     * allocators have also been removed in 1.6.0, so any 16-bit system now has
 101     * to implement a user memory handler.  This checks to be sure it isn't
 102     * called with big numbers.
 103     */
 104 #ifndef PNG_USER_MEM_SUPPORTED
 105    PNG_UNUSED(png_ptr)
 106 #endif
 107 
 108    /* Some compilers complain that this is always true.  However, it
 109     * can be false when integer overflow happens.
 110     */
 111    if (size > 0 && size <= PNG_SIZE_MAX
 112 #     ifdef PNG_MAX_MALLOC_64K
 113          && size <= 65536U
 114 #     endif
 115       )
 116    {
 117 #ifdef PNG_USER_MEM_SUPPORTED
 118       if (png_ptr != NULL && png_ptr->malloc_fn != NULL)
 119          return png_ptr->malloc_fn(png_constcast(png_structrp,png_ptr), size);
 120 
 121       else
 122 #endif
 123          return malloc((size_t)size); /* checked for truncation above */
 124    }
 125 
 126    else
 127       return NULL;
 128 }
 129 
 130 #if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
 131    defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
 132 /* This is really here only to work round a spurious warning in GCC 4.6 and 4.7
 133  * that arises because of the checks in png_realloc_array that are repeated in
 134  * png_malloc_array.
 135  */
 136 static png_voidp
 137 png_malloc_array_checked(png_const_structrp png_ptr, int nelements,
 138     size_t element_size)
 139 {
 140    png_alloc_size_t req = (png_alloc_size_t)nelements; /* known to be > 0 */
 141 
 142    if (req <= PNG_SIZE_MAX/element_size)
 143       return png_malloc_base(png_ptr, req * element_size);
 144 
 145    /* The failure case when the request is too large */
 146    return NULL;
 147 }
 148 
 149 PNG_FUNCTION(png_voidp /* PRIVATE */,
 150 png_malloc_array,(png_const_structrp png_ptr, int nelements,
 151     size_t element_size),PNG_ALLOCATED)
 152 {
 153    if (nelements <= 0 || element_size == 0)
 154       png_error(png_ptr, "internal error: array alloc");
 155 
 156    return png_malloc_array_checked(png_ptr, nelements, element_size);
 157 }
 158 
 159 PNG_FUNCTION(png_voidp /* PRIVATE */,
 160 png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array,
 161     int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED)
 162 {
 163    /* These are internal errors: */
 164    if (add_elements <= 0 || element_size == 0 || old_elements < 0 ||
 165       (old_array == NULL && old_elements > 0))
 166       png_error(png_ptr, "internal error: array realloc");
 167 
 168    /* Check for overflow on the elements count (so the caller does not have to
 169     * check.)
 170     */
 171    if (add_elements <= INT_MAX - old_elements)
 172    {
 173       png_voidp new_array = png_malloc_array_checked(png_ptr,
 174           old_elements+add_elements, element_size);
 175 
 176       if (new_array != NULL)
 177       {
 178          /* Because png_malloc_array worked the size calculations below cannot
 179           * overflow.
 180           */
 181          if (old_elements > 0)
 182             memcpy(new_array, old_array, element_size*(unsigned)old_elements);
 183 
 184          memset((char*)new_array + element_size*(unsigned)old_elements, 0,
 185              element_size*(unsigned)add_elements);
 186 
 187          return new_array;
 188       }
 189    }
 190 
 191    return NULL; /* error */
 192 }
 193 #endif /* TEXT || sPLT || STORE_UNKNOWN_CHUNKS */
 194 
 195 /* Various functions that have different error handling are derived from this.
 196  * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate
 197  * function png_malloc_default is also provided.
 198  */
 199 PNG_FUNCTION(png_voidp,PNGAPI
 200 png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
 201 {
 202    png_voidp ret;
 203 
 204    if (png_ptr == NULL)
 205       return NULL;
 206 
 207    ret = png_malloc_base(png_ptr, size);
 208 
 209    if (ret == NULL)
 210        png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */
 211 
 212    return ret;
 213 }
 214 
 215 #ifdef PNG_USER_MEM_SUPPORTED
 216 PNG_FUNCTION(png_voidp,PNGAPI
 217 png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size),
 218     PNG_ALLOCATED PNG_DEPRECATED)
 219 {
 220    png_voidp ret;
 221 
 222    if (png_ptr == NULL)
 223       return NULL;
 224 
 225    /* Passing 'NULL' here bypasses the application provided memory handler. */
 226    ret = png_malloc_base(NULL/*use malloc*/, size);
 227 
 228    if (ret == NULL)
 229       png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */
 230 
 231    return ret;
 232 }
 233 #endif /* USER_MEM */
 234 
 235 /* This function was added at libpng version 1.2.3.  The png_malloc_warn()
 236  * function will issue a png_warning and return NULL instead of issuing a
 237  * png_error, if it fails to allocate the requested memory.
 238  */
 239 PNG_FUNCTION(png_voidp,PNGAPI
 240 png_malloc_warn,(png_const_structrp png_ptr, png_alloc_size_t size),
 241     PNG_ALLOCATED)
 242 {
 243    if (png_ptr != NULL)
 244    {
 245       png_voidp ret = png_malloc_base(png_ptr, size);
 246 
 247       if (ret != NULL)
 248          return ret;
 249 
 250       png_warning(png_ptr, "Out of memory");
 251    }
 252 
 253    return NULL;
 254 }
 255 
 256 /* Free a pointer allocated by png_malloc().  If ptr is NULL, return
 257  * without taking any action.
 258  */
 259 void PNGAPI
 260 png_free(png_const_structrp png_ptr, png_voidp ptr)
 261 {
 262    if (png_ptr == NULL || ptr == NULL)
 263       return;
 264 
 265 #ifdef PNG_USER_MEM_SUPPORTED
 266    if (png_ptr->free_fn != NULL)
 267       png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr);
 268 
 269    else
 270       png_free_default(png_ptr, ptr);
 271 }
 272 
 273 PNG_FUNCTION(void,PNGAPI
 274 png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED)
 275 {
 276    if (png_ptr == NULL || ptr == NULL)
 277       return;
 278 #endif /* USER_MEM */
 279 
 280    free(ptr);
 281 }
 282 
 283 #ifdef PNG_USER_MEM_SUPPORTED
 284 /* This function is called when the application wants to use another method
 285  * of allocating and freeing memory.
 286  */
 287 void PNGAPI
 288 png_set_mem_fn(png_structrp png_ptr, png_voidp mem_ptr, png_malloc_ptr
 289   malloc_fn, png_free_ptr free_fn)
 290 {
 291    if (png_ptr != NULL)
 292    {
 293       png_ptr->mem_ptr = mem_ptr;
 294       png_ptr->malloc_fn = malloc_fn;
 295       png_ptr->free_fn = free_fn;
 296    }
 297 }
 298 
 299 /* This function returns a pointer to the mem_ptr associated with the user
 300  * functions.  The application should free any memory associated with this
 301  * pointer before png_write_destroy and png_read_destroy are called.
 302  */
 303 png_voidp PNGAPI
 304 png_get_mem_ptr(png_const_structrp png_ptr)
 305 {
 306    if (png_ptr == NULL)
 307       return NULL;
 308 
 309    return png_ptr->mem_ptr;
 310 }
 311 #endif /* USER_MEM */
 312 #endif /* READ || WRITE */
--- EOF ---